The only for sure way is a Pregnancy Test :)
I agree with Clysta....your post is really hard to understand. You need to take a pregnancy test. Many times women wrongly think that the second you get pregnant all these "symptoms" immediately start happening. That is not the way it works. Usually the lower back pains you are talking about don't happen until the end of a pregnancy anyway. Also having to urinate often is more of a second trimester thing too. I find that women think these things allot. Like on Yahoo answers many many questions are "could I be pregnant?" and then they follow up with a list of symptoms that they think they have. Then saying that it's too early to test just ends up making the symptom list make no sense. The hormone that gives you a positive pregnancy test is also one of the hormones that would cause some of those symptoms. Anyway, Ive gotten off track, sorry. Go take a test. You will know after a few minutes.
Your post is extremely difficult to follow. In answer to your question, you know if you're pregnant by taking a test and getting a positive.
Your symptoms are for the most part meaningless. All humans sleep, some more than others. You'll have days where you sleep more than usual too, it doesn't really mean too much. We all urinate as well, infection or increase in oral intake can cause a frequency in the trips. Back pain can be from strain, sleeping wrong or moving wrong.